Several groups have welcomed the recognition of Traveller’s minority ethnicity status.
The move will see Travellers incorporated into the anti-racism and integration infrastructure of the State.
It also means the group are automatically included in future domestic legislation.
The Irish Traveller Movement say the announcement was witnessed by Travellers from throughout the country in the Dáil gallery.
The group had called for State recognition for over 25 years, and more recently lead a campaign involving local and national organisations, as well as domestic and international human rights bodies.
President Michael D. Higgins has welcomed the move describing it as "a momentous decision".
He also says that he has written to the Travellers organisations that have campaigned on the issue to convey his congratulations and appreciation for their work.
In July 2015 the Attorney-General’s office said there was no impediment to State recognition of Travellers under two principle concerns, cost and additional legal implications.
Bernard Joyce, director of the Irish Traveller Movement, said: "Our recognition has been long outstanding, but today the State has made a closer step towards creating real equality for Travellers by acknowledging our unique identity and place in Irish society.
"Ethnicity is not the same as race, nationality or place of birth. I was born a Traveller it is my identity – I cannot become un – Traveller. I belong to a group who share a history that is our own - a culture, values, beliefs and language individual to us.
"Today is an acceptance of our dual identity of being both Irish and Traveller.
"Our desire as Travellers is to be valued for the people we are and the contribution we make to Irish society, but equally it is about improving our inclusion and enhancing our experience of being part of – rather than separate to as a group.
"We welcome the efforts of those who have contributed to creating the conditions to make today happen, and acknowledge also the two critical reports of the Oireachtas Committees on Justice on the matter.”
Outside the Dáil, Oein DeBhairduin of the Irish Traveller Movement spoke in the Traveller language Gammon - also known as Cant: "Mo geels, minʹúrt a nurt a lesk’art a lesko, A min’urt an donadu lesk dil ur gochlins.
"A min’urt stafa geiged. A min’urt a dil lesko a glughi a dil moniker a glori. A ned’es a min’urt a gugart. A ned’es a minurt a gaygin. A an minu’rt an dil gruber a flittered an.
"A min’urt an a geels a suwneed. A geels a goily suwneed a geels. Min’urt rinaltus suwnee our gils. A art suwneed, a tari a rinaltus. Stafara, a glori a geels.”
This translates as:
"It is not a day of gifting. It is not a day of begging. It day in which we worked and fought for. A day in which our people are seen. We have always seen each other. Today Ireland sees us. And in being seen - we speak to Ireland. May it listen to us".
Amnesty International has welcomed the Taoiseach's statement, with the group saying it has been a longstanding recommendation by the UN Committee for the Elimination of Racial Discrimination.
Colm O'Gorman, Executive Director of Amnesty International Ireland, said: "We welcome today’s historic announcement acknowledging Travellers’ unique identity as a distinct ethnic group. It is more than a symbolic step, but an important recognition of the community’s heritage and identity.
"Travellers in Ireland continue to suffer substantial levels of racial discrimination. They are more likely to be unemployed and living in poverty than people in the settled community.
"Today’s announcement is not about bestowing privileges, but ensuring that Travellers are able to achieve the same equality of opportunity and treatment to which everyone in Ireland, Traveller or settled, is entitled."
The Irish Council for Civil Liberties (ICCL) has also welcomed the move.
It says the "historic failure" to properly recognise Travellers as an ethnic group has long been viewed by the ICCL as contrary to international human rights law.
"This failure has served to fuel the mistrust, marginalisation and overt discrimination which has been the hallmark of relations between the majority ‘settled’ population and the Traveller community", the ICCL says.
Speaking in advance of the Taoiseach’s statement, executive director of the ICCL, Liam Herrick said: "Today’s announcement is truly historic event to be welcomed by all those who wish to see a society based on inclusion and respect.
"Recognition of Traveller ethnicity by the Government is a powerful statement that the history and tradition of Travellers is to be acknowledged, respected and valued.
"The recognition of Traveller ethnicity should mark a turning point in the treatment of Travellers in Irish society.”
While the Green Party also welcomed the recognition, saying the move was long overdue.
Green Party spokesperson for Community and Local Government, Malcolm Noonan, said: "We welcome the announcement that the Taoiseach is to formally recognise Traveller ethnicity in the Dáil today.
"Discrimination against Travellers coupled with poor outcomes in health and education and low employment opportunities have over decades compounded a multiplicity of problems that are unjust in a civilised society.
"Recognition of their ethnic minority status will give due recognition to their distinct culture and language and that it was a culture that should be celebrated and protected.